354 Reed: The mildews of the cereals 



■a 



rye, and wheat) belongs to a separate specialized form. The mil- 



5/ 



T. poloniatm, and 71 turgidunt, 

 mouococcum, barley, oats, or rye. 



{H. 



% t 



;') infected barley and also H. hexastichon^ H. jubatum, H. 



m^ H. nudum, and H. trifurcatum^ but not //. bulbosnm^ H. 



nuvi^ H. secalinuui^ oats, rye, or wheat. The mildew on 

 rye {Secale cereale) infected rye and S, anatolicuni, but not the 

 other cereals. The mildew on oats {Avcna sativd) infected oats 

 and also A, fatua^ A, orimtalis ^ d.wd Arrhcnatheruui elatius, but not 

 the other cereals. 



Salmon has also done considerable work with the grass mil- 



o 



dew, and while in general his results agree with those of Mar- 

 chal, yet there are some interesting minor differences. For 

 example, Salmon^* was unable to infect Arrhenaiherum elatius 

 with the oat mildew. In the case of the barley mildew, Salmon^ 

 found that conidia from barley infected Hordeum hulbosuui, //". 

 dcficiens, H, distichon, H, hexastichon^ H. inter medium, IL mart- 

 timum, H. vidgare, and H. Zeocriton, but not H. mhatiim, H. 



H. secalinum. or H. 



My 



with those of Marchal. I was not able to hifect barley, oats, 

 wheat, and twelve other grasses, all of which have been reported 

 as hosts of Erysiphe Graininis, while rye was readily infected with 

 conidia from the same host. 



During the past year I have carried out further extensive 

 experiments with the mildews of barley, rye, and wheat. While 

 at the University of Wisconsin, I had, as described in an earlier 

 paper, ^^ cultures of the rye and barley mildews growing in 

 the botanical greenhouse. '|, Through the kindness of Professor R. 

 A. Harper, cultures of these mildews were forwarded to me at 

 Columbia, Missouri. The wheat mildew was first found in the 

 fall of 1907, at Columbia, on wheat plants brought into the green- 

 house from the field^or^experimental work. In a few days after 

 these plants were brought^in, the mildew was observed to be pres- 

 ent. The fungus spread very rapidly and cultures have been 

 kept growing ever since. 



r 



I am indebted to*a number of people for furnishing me with 



